Performance analysis of high rate linear codes over precoded ISI channels

In this paper, we discuss an approach for analyzing the serial concatenation of a high rate convolutional code and a preceded intersymbol interference (ISl) channel. The proposed approach is simple and can be used to identify the preceder that results in the lowest error rate floor analytically without resorting to simulations. Also, the proposed approach can be used to enhance the interleaver design to achieve further performance improvement. We extend the proposed technique to fading ISI channels using statistical models of these channels. Simulation results suggest that the optimal preceder, when selected based on the statistical model of the channel, is optimal or somewhat optimal for the time varying channel. We finally remark that the proposed analytical approach is not limited to high rate convolutional codes, but it also applies to arbitrary high rate linear outer codes.